1. Field of the Invention
The present invention relates to a torque transmission apparatus for transmitting rotation of a driving unit to a driven unit.
2. Related Art
An Oldham coupling is known as a shaft coupling that can be applied in case where the central axis of a driving unit and the central axis of a driven unit can deviate from each other so as to keep them in parallel with each other. As shown in FIG. 34, an intermediate plate 3 serving as a floating cam is inserted between a driving unit 1 and a driven unit 2, so as to deviate freely during rotation thereof. Rotation of the driving unit 1 causes the intermediate plate 3 to rotate at the same rotational speed, while sliding relative to the driving unit 1, and also causes the driven unit 3 to rotate at the same rotational speed, while sliding relative to the intermediate plate 3. The intermediate plate 3 is provided with projections 3a, 3b, which slide relative to the driving unit 1 and the driven unit 2, respectively, while being subjected to pressure applied therefrom during rotation.
Transmission of a large torque with the use of Oldham coupling requires a large floating cam. This causes an increased weight of the whole coupling. In addition, it is difficult to decrease the thickness of the coupling, and more specifically, to achieve miniaturization of the coupling in a direction of the central axis thereof.